5.15.1. Performing Maintenance on a Single Slave

Performing maintenance on a single slave can be achieved by temporarily
shunning the slave (while in
AUTOMATIC policy mode) and
doing the necessary maintenance. Shunning a datasource in this way will
temporarily remove it from the dataservice, and prevent active and new
connections from using the datasource for operations.

The steps are:

Shun the slave:

[LOGICAL:EXPERT] /alpha > datasource host2 shun

Shunning a datasource does not put the replicator offline, so the
replicator should also be put in the offline state to prevent
replication and changes being applied to the database:

[LOGICAL:EXPERT] /alpha > replicator host2 offline

Perform the required maintenance, including updating the operating
system, software or hardware changes.

Validate the server configuration :

shell> tpm validate

Recover the slave back to the dataservice:

[LOGICAL:EXPERT] /alpha > datasource host2 recover

Once the datasource is added back to the dataservice, the status of the
node should be checked to ensure that the datasource has been correctly
added back, and the node is ONLINE
and up to date.

While the datasource is shunned, the node can be shutdown, restarted,
upgraded, or any other maintenance. Throughout the process, the slave
should be monitored to ensure that the datasource is correctly added
back into the dataservice, and has caught up with the master. Any
problems should be addressed immediately.